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Bigger tires less Grunt :(

3K views 45 replies 16 participants last post by  EatTacoCatTea 
#1 ·
Hello again!
So I'm loving my new 33"s but I'm not loving having to change gear when driving into wind/up hill on the motorway.
Is there any cheap ish way I can get back some of the power I have lost by upping the tire size?
Fighting the urge to buy a 2JZ so any suggestions would be realy helpful in stopping me do something daft!

Thanks again
 
#4 ·
Regearing is the only fix for that. No bolt-ons will help so don't even consider throttle body spacers, cold-air intakes, chips, etc. None of those will help in the least... not even close.

Regearing to the right ratio will restore the lost power and dramatically boost the performance. What engine and transmission do you have?
 
#5 ·
the programmers that change shift points are a start, though some don't think of this as a first alternative...unless yours is a 5spd. if so, then i'm afraid you're better off re-gearing your diffs. mine is an automatic so i opted for the chip...kept bouncing back and forth between 2nd and 3rd, 3rd and overdrive on flat road. helped the gear jumping but the shifts were more firm than i desire.

i would have re-geared for a little extra to have it back to normal the first time considering it was $200 more than the chip. this shop where i live does it for $100 per axle so long as you provide the parts (R&P, master installation kit, oil, etc.)
 
#7 ·
i hear a lot of guys swapping axles with desirable gearing already installed, and even after you consider having to weld new brackets to adapt it to a tj suspension (even if you have to pay someone to do it), it still comes out, in some cases, a little cheaper than re-gearing your existing axles.

for the guys swapping out the rear and matching the front diff ratio, the price is just under what you'd pay for re-gearing both existing axles...but depending what they charge for labor in your area. now you got some more homework (^_^)
 
#10 ·
3.07 is an abysmal ratio for even 30" tires, let alone your 33's. 4.56 is the appropriate ratio for 33" tires with your manual transmission and 4.0L engine combination which will produce a dramatic improvement in power, back to what it was when it left the factory.
 
#11 ·
i totally agree with Jerry. i forgot how perky the jeep was before i went with bigger tires until i re-geared to a 4.56 gear set. you mentioned "motorway", tell me what those speeds are like. because some guys like to run 4.10s in theirs if they have to drive at higher rates of speed for distances across a few counties in a state. it keeps the RPMs down while in overdrive, and saves the waterpump and your cooling system in the process. and although there is a difference in power restoration between the two gear sets, the effects aren't too significant IMO.

so if you go slow for short distance commutes especially on the "motorway", 4.56s would be my first choice especially if the jeep is going to be wheeled off road on a weekend or two. but if it sees more long "motorway" commutes, then a 4.10 gear set would be a good option too.
 
#12 ·
hey btw Jim, how do you like your 6spd, like how does it handle in town with the 33s and 4.0L? there's a guy in my area selling one from a wreck for, what i understand to be, a reasonable price and am not able to find an ax-15 or NV3550 for less than that, especially where i live. there are cheap ones in the upper 48 but getting anything to Hawaii is never cheap (T_T)
 
#13 ·
My jeep is a daily drive but we have some good weekend off roading round here too. I don't go on the motorway more than once a month usually, so 4.56 will be the one I'm going to look at.

As for my feelings towards the 6spd then I can't fault it with the stock tires,
I't hasn't let me down yet and has got me home in snow storms that has seen many sleeping in their cars.
I hear its a Mercedes built gear box but i don't know how true that is.
I have only test driven the 5spd so my opinion can't bear too much weight but until i fit the 33"s then I wouldn't have changed it for the world
 
#19 ·
yes, per novak, they paired up with merc for the NSG370 gearbox. i hear people say first gear is rather low for taking off and second is a bit tall as well with this transmission. so it tends to be annoying at times for them on the streets. great for offroad otherwise. i was just wondering what your outlook on this was in your experience with the 33s and your current gear set. thanks :smile:

they are known for bending shift forks, however. one would say that shifting through certain gears may chirp or even miss a gear because of misaligned synchros for that matter, and some other gremlins floating around. the jk guys are also finding this to be true even at less than or up to 1000 miles on the odometer which is rather disappointing to hear. the 2004 models were the most notorious for the most issues if i remember correctly.
 
#21 ·
x3 adamc55 haha!!

DaJeepNotCheap I could easily live with the gear ratio as is with the 33"s but It feels under powered once you get out of 3rd gear also i find that i have to build the revs in 1st more than i like if i need to leave a junction at speed.
As for gremlins then I can happily say that I haven't found any yet but its a 2005 model with only 58,000 miles on it. I sometimes have to double clutch to get it to engage reverse and the 4WD stick can be a pain but this all started after I installed the body lift.
I'm getting a 1" motor lift soon though which hopefully will eradicate this.
Has anyone else tried the 6spd 3.007 with 33"s and 4.56 gears? (Might ask this in another post)
 
#23 ·
I had a good shop here in Las Vegas install my 4.56's (I have 33's also) and made a great improvement. They didn't recommend the 4.10's, which is what I originally wanted, because they said you won't feel much difference from stock. I kind of wish I would've gone with the next gear ratio up to 4.88's. Either way, I'm happy with it. The shop has a chart on gear to tire ratio's too:

http://adamsdriveshaftoffroad.com
 
#25 ·
Hello again!
So I'm loving my new 33"s but I'm not loving having to change gear when driving into wind/up hill on the motorway.

Thanks again
Thats why it is made with 6 different ratios !!!!

Even if you put in 4.56s you might still have to shift.

Blows me away how people think driving is about putting it in high gear and pushing on the go pedal.

BUY AN AUTOMATIC !!
 
#28 ·
You miss the point.
I just want the previous power back before 33"s not a car that will never leave 6th gear.
An automatic isn't an option either here in the U.K. Hard to find and slightly socially unacceptable.

C.L. Thanks for clearing that up, breathing a bit easier now.
 
#27 ·
That's what I wonder about too.

It seems to be a psychological strain to drive in a gear lower than the tranny's highest.
Driving in too high a gear will cause "strain".

Ever ride a multi speed bicycle? You are the engine. You are in the highest gear and you want to pick up speed. How hard is it on you in the highest gear? Downshift and it is easier, correct?

You come up on an incline. Is it harder on you (engine) in the highest gear or do you downshift vs huffing, puffing and loosing speed?
 
#32 ·
True but it would mean a huge waste of money on lifts and rims etc...
Also the 33"s have opened up a much wider range of trails for me and I love em!

Can Anyone tell me what the tag would say on my rear pumpkin if it was an open diff?
hopefully you can see the image of the tag I have posted

 
#34 ·
T
Can Anyone tell me what the tag would say on my rear pumpkin if it was an open diff?
hopefully you can see the image of the tag I have posted


The tag will not indicate it. Get a build sheet for you jeep. I will have your exact configuration as built.

Don't remember what it is called on Jeep but on other Chrysler products it is listed as "anti-spin" if it is a limited slip
 
#35 ·
it sounds,& is a lot of money but I wish I had mine done sooner.I did gears(4.56) when I did my lockers.Figured Id just get it all done and over with
 
#36 ·
Yeah I have decided I'm going for gears and lockers now but don't know weather to get a Detroit locker or save up a bit and gear ARB air lockers. I can get a lot of snow here and loads of ice so the more expensive may be the cheaper in the long term if it saves me writing off my jeep.
In the U.K it'll cost me £1000 for gears and Detroit lockers or £2500 for ARB gears and air lockers.
 
#37 ·
Detroit Lockers are SUPERB but they're not superb on ice. Before I got my Detroit Locker, I followed some Jeeps with Detroit Lockers through some icy trails and they were sliding sideways/downwards on the iced up off-camber sections a lot. With much snow & ice, I'd recommend an ARB Air Locker or Eaton E-Locker.
 
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